Paper manufacture



March 24, 1942- c. RJCRAWFORD PAPER MANUFACTURE Filed Aug. 17, 1939 Patented Mar. 24, 1942 UNITED- STATE s YPATENT" OFFICE PAPER MANUFACTURE milton, Ohio, assignor to The Black-Clawson Company, Hamilton, Ohio, a corporation of Ohio Application August 17-, 1939, Serial No. 290,588 2 Claims. -(CI. 92-37) Cliff R. Crawford, Ha

, circulated, the tank having a supply trough above the supply and discharge ends of the tank providing controllable overflow streams of stock to the supply end and to the discharge end of the tank.

Other objects and advantages of the invention will be apparent from the following description, the appended claims and the accompanyin drawing, in which: I

Fig. 1 is a, perspective view of a tank embodying the present invention, a portion of the wall structure. being removed for purposes of illustration: r V

Fig. 2 is avertical sectional 'view through the discharge end of the tank; and Fig. 3 is the top plan view showing the end of the tank.

Referrlng more particularly to the drawing,

in which a preferred embodiment of the invention has been illustrated, it generally designates the enclosing wall of a stock handling tank adapted for the circulation of paper stock. As herein shown the tank maybe used as a part of 1 a pulping apparatus by supplying pulp laps and water tothe tank and circulating the same by gravity action around the vertical midfeather II from the supply end I2 to the discharge end l3 of the tank, the material then travelling through a downwardly tapering discharge passage H to a series of rotatable high speed beating blades l5 which are operated by an electric motor H5 or the like. The blades l5 act as an effective pulp-' ing means so that the stock which flows through the passage Hi will be shredded, beaten and whirled and then supplied to an impact impeller contained in the impeller casing ll which acts to force the stock up through the pipe l8 for return to the tank. The tank may also be used as a color mixer or may be used as an agitating means to maintain the stock in a constant state of agitation until it is supplied by a centrifugal pump 20 through the take-oil pipe l9 to additional refining means or to a paper making machine.

The stock that is returned through the upwardly extending pipe l8 enters a trough 2| which is arranged at a level considerably above that of the discharge passage l4. This trough extends across-the tank above the material in the supply end and the discharge end and provides a chamber 22 extending the full width of the supply end, and an auxiliary chamber or passage 23 extending across the tankrabove the discharge end. The chamber 22 has an upwardly extending wall portion 24 over which the stock flows throughout the width of the supply end of the tank onto the stock in the tank, thus giving an even distribution of the stock supply to the tank, and causing a continuous intermixing action with the avoidance of stratification and unagitated areas. Since the stock falls from the chamber 22 onto the stock already in the tank any foam andfloating stock at the supply end will be promptly submerged. If the tank is used for color diffusion the color will be promptly distributed to the entire body of stock at the supply end, and an effective blending action will take place at this point, the color diffusion being continued as the stock travels around the midfeather II and returns to the discharge passage ll.

The chamber 22 is in communication with the auxiliary chamber 23. which extends over the discharge end of the vat-through the opening 25 in the midfeather. Stock overflows an upstanding wall portion 26 and falls onto the stock in the tank adjacent the tank outlet and thus submerges the foam and submerges any lighter or floating pieces of pulp so they may be more readily carried downwardly and enter the discharge passage The fall over the wall portion 26 is distributed throughout the width of the discharge end of the vat.

The rate at which the recirculated stock is supplied ,over the wall portion 28 is controllable so that about 10% to 15% otthe recirculated stock returned by pipe l8,can be bypassed over the wall portion 26 while the remainder is supplied over the overflow wall of the chamber 22 to the supply end of the vat and thus caused to erably both the supply chamber 22 and the chamber or passage 23 are provided with .ad-.

justable boards or dams 28 guided for vertical sliding movement along the side or wall portion 25, the height of thedams being independently controllable so asto give the desired rate of flow height of the dam at the supply end of the vat.

Both the chamber 22 and the chamber 23 are provided with clean-out holes 34, or limited size, I

and arranged in the bottom walls of these chambers so'that when the vat is to be cleaned'the materialtin these chambers can drain completelyv into the vet. The flow through these holes 34 also gives a limited diffusing or mixing action duringnormal operation.

While the form of apparatus herein described constitutes a preferred embodiment of the in-.

vention, it is to be understood that the invention is not limited to this precise form of apparatus,

and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. Paper stock handling apparatus of the character described comprising a tank having an end wall and asubstantially verticalbaffie extending from the end wall to a point spaced from the opposite end of the tank and providing for the'circulation of stock in a path of substantially horseshoe form from a supply zone at one side of the baflle to a discharge zone along side of the supply zone at the other side of the baflle, said tank hav-- ing a horizontally extending trough at an elevated location extending from side to side of the tank and across the supply zone and the discharge zone, said trough having an adjustable wall above the supply zone over which stock flows throughout substantially the entire width of the supply zone onto the stock in the tank and having a second adjustable wall over the discharge zone over which stock flows throughout substantially the entire width of the discharge zone onto the stock in the tank, and means for withdrawing stock from the discharge zone at one side of the baflle and forcing it up into said trough at the other 'side of-the baflie.

2. Paper stock handling apparatus or the character described comprising a tank having an end wall and a substantially vertical battle extending from the end wall to a point spaced from the opposite end of the tank and providing for the circulation of stock in a path of substantially horse-v shoe form from a supply zone at one side of the battle to a discharge zone along side or the supply zone at the other side of the baille, said tank having a horizontally extending trough at an elevated location extending from side to side of the tank and across the supply zone and the discharge zone, said trough having an adjustable wall above the supply zone over which stock flows throughoutsubstantially the entire width of the supply zone onto the stock in the tank and hav-v ing a second adjustable wall over the discharge zone over which stock flows throughout substantially the entire width of the discharge zone onto the stock in the tank, and means for withdrawing stock from'the discharge zone at one side of the baflie and forcing it up into said trough at the other side of the baflle, means for independently controlling the height of said adjustable walls,

said trough having drain openings at the bottom portions thereof.

1 CLIFF R. CRAWFORD. 

